With development of highly integrated microwave chips, a problem of spatial leakage in a chip has become a bottleneck of microwave chip performance improvement. For a common microwave integrated chip with an architecture of an upconverter and a tunable attenuator, local oscillator leakage caused by insufficient isolation is hard to be resolved by using a conventional quadrature modulation correction (QMC) solution. A local oscillator suppression filter is hard to be implemented in a high frequency band, and cannot be integrated inside the chip. Local oscillator leakage seriously affects transmit power precision, transmitter spurious emission, and link linearity.
Therefore, how to effectively suppress local oscillator leakage caused by insufficient spatial isolation inside a microwave chip is an issue to be resolved urgently.